Solve: + ⁺15 + ⁻4 + ⁻11.
Solve: - ⁺1 - ⁺0 + ⁻11 + ⁺8.
Solve: - ⁺0 + ⁺9 + ⁻11 - ⁺23.
Solve: - ⁺0 + ⁻3 X - ⁺9 + ⁺5
Solve: + ⁺3 X - ⁺15.
